The approaches described in this section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Carriers providing multimedia over IP services often use session border controllers for various reasons including security, remote (far-end) NAT traversal, topology hiding, compliance with the Communications Assistance for Law Enforcement Ace (CALEA), Call Admission Control, and others. A Session Border Controller usually deals with both signaling (by interacting with a Signaling Controller [SC] subsystem) and media (by interacting with a Media Controller [MC] subsystem). In the general case the SC often manipulates multimedia signaling to cause the subsequent media streams to flow through the MC. While some applications, such as CALEA, mandate this behavior, in many other applications, such as hosted NAT traversal, it is better not to have all the media flow through the MC, e.g. for traffic engineering reasons.
Certain proposals call for adding intelligence into the multimedia endpoints, and supporting protocols such as STUN and frameworks such as ICE. STUN is defined in Internet Engineering Task Force (IETF) Request for Comments (RFC) 3489. ICE is defined in an IETF “internet-draft” that is available at the time of this writing in the “internet-drafts” folder of the domain “ietf.org” on the World Wide Web. However, many standard multimedia endpoints do not have any such embedded intelligence. Therefore, there is a need in this field to provide ways to manipulate multimedia signaling without requiring multimedia endpoints to incorporate such embedded intelligence.